"In the sixteenth century the Republic of Siena played an important role in the development of the Renaissance. The contribution Sienese writers made to Italian literature and history is still to be written, but it is impressive to see how many men, and women were part of it. One such case is represented by the scholar and writer Lattanzio Benucci, born near Siena in 1521. A cultured member of the nobility, Benucci studied at the local university and then served his city as ambassador to Florence, where he entered the salon of the poet and courtesan Tullia d’Aragona. Subsequently, Benucci moved to Rome where he was a courtier first of Cardinal Antonio Trivulzio and then of Cardinal Alfonso Carafa. In 1565 Benucci returned to Siena. Duke Cosimo de’ Medici employed him in Florence, where he died in 1598. The details of his biography are analyzed in the first chapter of this thesis. Over the centuries, some of Benucci’s literary works were lost. What has survived, however, is very revealing of his learning and letters: at least three poetry collections (see the second chapter), together with some others transcribed after his death (analyzed in the third chapter), a Dialogo de la lontananza (“Dialogue on Distance”), and a commentary (Osservazioni) on Dante’s Divine Comedy (both examined in the fourth chapter). All these works are still unpublished : in the second volume of this thesis, most of them have been transcribed in five appendices with philological apparatuses. This dissertation aims not only to increase our knowledge of a productive and well-connected intellectual of the sixteenth century, but also at offering a much more nuanced understanding of the complexity of late Renaissance Humanism. In so doing, it helps to shift the traditional focus away from much-examined Florence, Rome, and Venice, in order to place it on another crucially important city, Siena, and thereby widen our views on Renaissance Italy."